Distinct axo-somato-dendritic distributions of three potassium channels in CA1 hippocampal pyramidal cells

Tekla Kirizs, Katalin Kerti-Szigeti, Andrea Lorincz, Z. Nusser

Research output: Contribution to journalArticle

27 Citations (Scopus)

Abstract

Potassium channels comprise the most diverse family of ion channels and play critical roles in a large variety of physiological and pathological processes. In addition to their molecular diversity, variations in their distributions and densities on the axo-somato-dendritic surface of neurons are key parameters in determining their functional impact. Despite extensive electrophysiological and anatomical investigations, the exact location and densities of most K+ channels in small subcellular compartments are still unknown. Here we aimed at providing a quantitative surface map of two delayed-rectifier (Kv1.1 and Kv2.1) and one G-protein-gated inwardly rectifying (Kir3.2) K+ channel subunits on hippocampal CA1 pyramidal cells (PCs). Freeze-fracture replica immunogold labelling was employed to determine the relative densities of these K+ channel subunits in 18 axo-somato-dendritic compartments. Significant densities of the Kv1.1 subunit were detected on axon initial segments (AISs) and axon terminals, with an approximately eight-fold lower density in the latter compartment. The Kv2.1 subunit was found in somatic, proximal dendritic and AIS plasma membranes at approximately the same densities. This subunit has a non-uniform plasma membrane distribution; Kv2.1 clusters are frequently adjacent to, but never overlap with, GABAergic synapses. A quasi-linear increase in the Kir3.2 subunit density along the dendrites of PCs was detected, showing no significant difference between apical dendritic shafts, oblique dendrites or dendritic spines at the same distance from the soma. Our results demonstrate that each subunit has a unique cell-surface distribution pattern, and predict their differential involvement in synaptic integration and output generation at distinct subcellular compartments.

Original languageEnglish
Pages (from-to)1771-1783
Number of pages13
JournalEuropean Journal of Neuroscience
Volume39
Issue number11
DOIs
Publication statusPublished - 2014

Fingerprint

Pyramidal Cells
Potassium Channels
Dendrites
Cell Membrane
Physiological Phenomena
Inwardly Rectifying Potassium Channel
Dendritic Spines
Specific Gravity
Presynaptic Terminals
Carisoprodol
Pathologic Processes
Ion Channels
GTP-Binding Proteins
Synapses
Neurons
Axon Initial Segment

Keywords

  • Confocal microscopy
  • Electron microscopy
  • Immunohistochemistry
  • Ion channels

ASJC Scopus subject areas

  • Neuroscience(all)
  • Medicine(all)

Cite this

Distinct axo-somato-dendritic distributions of three potassium channels in CA1 hippocampal pyramidal cells. / Kirizs, Tekla; Kerti-Szigeti, Katalin; Lorincz, Andrea; Nusser, Z.

In: European Journal of Neuroscience, Vol. 39, No. 11, 2014, p. 1771-1783.

Research output: Contribution to journalArticle

Kirizs, Tekla ; Kerti-Szigeti, Katalin ; Lorincz, Andrea ; Nusser, Z. / Distinct axo-somato-dendritic distributions of three potassium channels in CA1 hippocampal pyramidal cells. In: European Journal of Neuroscience. 2014 ; Vol. 39, No. 11. pp. 1771-1783.
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